'tv 


.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY     CIRCULAR  fa  161, 

L.  O.   HOWARD.   F-ntomoloB-Ul  •>. id<  !..  -f..|  [iurrau. 


THE  MANIPULATION  or  Till':  WAX 
SCALES  OF  THE  HONEY  BEE. 


BY 


I).  B.  CASTEEL,  Pit.  D., 
••  r:  Adju  Zoology, 


■  .ro«  :  GOVERNMENT  PftlNTINO  OFFICE  :  t »I2 


BUREAU  OF  ENTOMOLOGY. 

L.  O.  Howard,  Entomologist  and  Chief  of  Bureau. 

C.  L.  Mari.att,  Entomologist  and  Acting  Chief  in  Absence  of  Chief. 

R.  S.  Clifton,  Executive  Assistant. 
W.  P.  Tastf.t,  Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investiga- 
tions. 

A.  D.  Hopkins,  in  charge  of  forest  insect  investigations. 
W.  D.  Hunter,  in  charge  of  southern  field  crop  insect  investigations. 
'    M.  Websteb,  in  charge  of  cereal  and  forage  insect  investigations. 
-v.  L.  Quaintance,  in  charge  of  deciduous  fruit  insect  investigations, 
vl  F.  Phillips,  in  charge  of  bee  culture. 

I>.  M?.  rtO&EBS,  in  charge  of  preventing  spread  of  .moths,  field  work. 
Rolla  P.  Currie,  in  charge  of  editorial  work. 
Mabel  Colcord,  in  charge  of  library. 

Investigations  in  Bee  Culture. 

B.  P.  Phillips,  in  charge. 

G.  P.  White,  J.  A.  Nelson,  experts. 

G.  S.  Demutii,  A.  H.  McCbay,  X.  E.  McIndoo,  apicultural  assistants. 

D.  B.  Casteel,  collaborator. 
Pearle  II.  Gabrison,  preparator. 


ADDITIONAL  COPIES  of  this  publication 
Xi.  may  be  procured  from  the  Superintend- 
ent of  Documents,  Government  Printing 
OHice,  Washington,  D.  C,  at  5  cents  per  copy 


Circular  No.  161. 

I  nitcd  States  Department  of  Agriculture, 

BUREAU   OK  ENTOMOLOGY. 
L.   O.    HOWARD,    Entomologist    and    Chief   of    Bureau. 


Till:  IANIPULATION  OF  Till,  WAX  SCALES  OF  THE 

BONET  BEE. 

By  D.  B.  Oasti  i  i..  I'll.  l>. 

Collaborator;  Adjunct  Professor  <>f  Zoology,  University  of  Texas, 

I  n  1 1:<  ©1  CTI<  >N. 

Tlu"  particular  form  of  bee  activity  with  which  this  paper  deals 
is  that  which  results  in  the  removal  of  the  wax  scales  from  the  bodies 
of  the  worker  bees  and  in  the  application  to  the  comb  of  the  wax 
thus  obtained.  A  detailed  presentation  of  tin-  facts  will  he  given 
ami  attention  called  to  certain  current  conceptions  of  this  process 
which  arc  in  error. 

Since  the  bee  IS  a  very  lively  Lnsecl  it  IS  not  surprising  that  the 
bodily  movements  upon  which  some  of  it-  activities  depend  are 
extremely  difficult  to  follow  ami  may  easily  he  misunderstood.  All 
of  its  highly  specialized  legs  may  he  u-ed  at  once  in  the  performance 
of  some  intricate  process,  ami  the  observer  is  in  need  of  keenness  of 
-~ i ltIi I  and  patience  if  he  would  gain  more  than  an  approximate 
understanding  of  the  parts  taken  by  tlu1  several  members. 

In  the  more  permanent  literature  of  apiculture  and  of  zoology 

will   he    found   well-written   account-  of  the  habits  of  lice-,   accounts 

which  are  founded  upon  a  large  amount  of  careful  observation  and 
which  represent  the  work  of  many  students  of  bees  from  the  time 
of  lluher  on.  As  the  years  have  gone  by,  errors  of  sight  and  of 
judgmenl  have  gradually  been  eliminated,  so  that  at  the  present  time 
our  knowledge  of  bee  life,  so  far  a-  it  goes,  rests  upon  a  fairly 
satisfactory  foundation  of  authenticated  facts.  Yet  many  puzzling 
questions  are  still  unanswered,  and  some  supposed  fact-  may  Mill  he 
doubted. 

An  examination  of  a   number  of  bees    from   an  active  colony   will 
show  great   variation  in  the  appearance  of  the  wax  scales  of  ditf'er- 
.m.-.u.-,     -dr.  101—12  1 


2  MANIPULATION   OF   WAX   SCALES   OF   THE   HONEY  BEE. 

ent  members  of  the  colony.  In  some  cases  no  scales  can  be  observed, 
even  upon  dissection.  In  others  the  scales  will  be  found  to  be  ex- 
tremely thick  and  completely  filling  the  wax  pockets.  Some  bees 
will  show  scales  in  two  or  three  pockets  and  none  in  others.  Many 
of  the  workers  will  possess  a  complete  supply  of  scales,  either  all 
of  about  the  same  thickness  or  varying  considerably  in  thickn 
These  and  other  diverse  conditions  present  themselves  for  explana- 
tion. 

The  present  account  is  particularly  concerned  with  the  manipula- 
tion of  the  wax  scales.  By  what  process  or  series  of  processes  are 
the  scales  of  wax  removed  from  their  pockets  and  added  to  the 
comb?  That  the  wax  which  forms  the  comb  is  produced  by  the  bees 
themselves,  being  elaborated  within  their  bodies  and  given  out  in  the 
form  of  thin  plates  or  scales,  is  a  fact  well  known  to  all  students 
of  bees;  but  many  differences  of  opinion  have  been  expressed  con- 
cerning the  exact  method  of  wax  manipulation.  It  is  also  well 
known  that  the  workers  of  the  hive  perform  many  duties — build- 
ing the  comb,  gathering  the  stores  of  pollen  and  honey,  caring  for 
the  brood  and  the  queen,  repairing,  cleaning,  ventilating,  and  guard- 
ing the  hive — and  it  has  been  fairly  well  established  that  in  some 
cases,  at  least,  these  duties  vary  with  the  age  of  the  individual 
Avorker,  although  more  accurate  information  on  this  point  is  much 
to  be  desired.  Dreyling's  1  results,  in  particular,  indicate  that  bees 
of  certain  ages  are  incapable  of  producing  wax,  since  their  glands 
s;re  either  undeveloped  or  atrophied.  Do  these  bees  use  the  wax 
secreted  by  others,  taking  it  from  them,  manipulating  it,  and  form- 
ing it  into  comb?  By  careful  observation  bees  devoid  of  wax  scales 
or  with  scales  too  thin  for  satisfactory  removal  ma}*  be  discovered 
working  with  the  wax.  Do  these  bees  procure  their  wax  from  other 
workers,  or  are  the}7  merely  reworking  the  wax  of  the  comb?  Upon 
each  hind  leg  of  a  worker  bee  is  located  a  peculiar  pincers-like 
structure  long  known  as  the  wax  shears.  Do  bees  really  use  this 
instrument  in  extracting  the  scales  from  the  pockets,  and  if  so,  does 
the  owner  of  the  scale  perform  this  operation,  or  is  the  scale  re- 
moved by  another  worker?  Or  may  it  not  be  that  the  wax  scale-- 
drop  from  their  pockets  when  they  reach  a  suitable  thickness,  and 
are  salvaged  by  other  workers  and  added  to  the  comb?  All  of  the 
above  interpretations  of  these  processes  have  been  advanced  by 
various  observers.  It  is  the  object  of  this  paper  to  present  a  true 
account  of  the  manner  in  which  the  scales  of  wax  are  transported 
from  their  pockets  to  the  comb  and  to  point  out  some  of  the  causes 
which  lead  to  diversity  in  scale  number  and  scale  form. 

1  Drpylinp,  I..  1903.  Ueber  dip  wacbbereitenden  Organo  dor  Ilonigbiene.  Zoologiscber 
Anzeiger,  Vol.  26. 

Same. — 1905.  Die  wachboroitondon  Organc  bei  don  geselUg  lebondon  Iiionou.  Zoolo- 
fiisclio  Jahrbiicher,  Abthellung  fur  Anatomic  u.  OntoRonie  d.  Tbloro,  Vol.  22. 


M  \NI1-I    I    \  I  luN    OF    WW    SCALES   Ot      INK    llo.M 


i  ii  i     u  \\ii:i  in  <  i  m.   (iiu;  \  ss. 


Th"  way  in  which  the  was  Bcales  arc  formed,  a-  secretion  products 
arising  from  the  surfaces  of  the  wax  plates  on  the  ventral  side  of 
the  abdomen  <>f  the  workers,  has  been  well  described  by  others  and 
with  apparent  accuracy.  The  accounts  <•!  Dreyling  embody  the 
results  of  a  very  considerable  amount  of  work,  ami  will,  for  the 
present,  at  least,  It  taken  at  their  lull  value.  The  work  of  Snod- 
»nbs '  upon  the  anatomy  of  the  "wax  plate-  and  wax  glands  may  be 
relied  upon.  Only  a  brief  statement  will  here  It  given  of  the  struc- 
ture of  these  organs  and  of  the  manner  in  which  the  scales  are 
formed. 

\  \t  well  known,  wax  is  produced  by  the  worker  bees  only.  The 
location  of  the  wax-secreting  sur- 
faces, or  wax  plates,  may  he  readily 
determined  by  an  examination  of  the 
ventral  surface  of  a  bee's  abdomen. 
By  stretching  the  abdomen  Bomewhat 

it    w  ill   he  seen   that    each  of  the   last 

four  visible  sternal  or  ventral  plates 
i-  divided  into  two  regions:  A  pos- 
terior projecting  edge  which  i-  dis- 
tinctly hairy,  and  a  smooth  anterior 
half  which   is  usually  covered  by  the 

next  preceding  plate.  Thi-  anteri<  r 
region  is  divided  by  a  median  ridge 
into  two  distinct,  irregularly  oval 
hich  thus  lie  on  either  side 
of  the  midventral  line.  These  area- 
arc  the  wax  plate-,  and  upon  them 
the  wax  scales  are  formed.  Each  one 
of  the  last  four  sternal  plate-  bears 
two  wax  plates,  making  eight  in  all. 
(S     Bg.l.) 

The  glands  which  -ci  rite  the  \\;i\ 
lie  on  the  floor  of  the  abdomen  im- 
mediately above  and  in  contact  with  the  wax  plate-,  and  their 
secretion  is  deposited  upon  the  externa]  surfaces  of  the  plates,  exud- 
ing through  the  many  minute  pore- which  perforate  the  plates.  Upon 
coming  in  contact  with  the  air  the  fluid  wax  hardens,  forming  a  cov- 
ering over  the  entire  outer  surface  of  the  plate,  which  gradually  in- 
creases in  thickness  with  the  continued  addition  of  wax  through  the 
pores.    Tn  this  way  the  wax  scales  are  produced,  and  since  they  are 


l'n;.  i      Ventral    abdominal    pintra 
nf  -.\  w  oi  isected  to  -how 

the  position  of  the  wai  plates. 


■  Bnodcnn,  B    r  .   1810     The  Anatomy  of  the  Floney  Bee,  Bur.  Bnt,  Tech.  s-r.   18, 
i     s    Dept   Agt 


4  MANIPULATION    OF   WAX   SCALES   OF   THE   HONEY   BEE. 

molded  upon  the  surfaces  of  the  eight  wax  plates  they  correspond  to 
them  in  number  and  in  form. 

In  its  natural  position  each  wax  scale  lies  between  its  wax  plate 
and  the  overlapping  edge  of  the  next  preceding  sternal  plate.  The 
scale  thus  fits  into  a  little  crevice  or  wax  pocket  and  is  well  protected 
from  injury.  If  the  bee  extends  its  abdomen  the  rear  edges  of  the 
scales  can  be  seen  protruding  from  their  pockets,  or  if  the  scales  be- 
come very  thick  they  will  push  the  covering  sternal  plates  outward 
and  will  project  from  the  pockets. 

THE   FORMATION    OF   THE   WAX    SCALES. 

The  problem  of  wax  secretion  has  been  extensively  studied  by 
Dreyling,  who  shows  that  the  wax  glands  differ  markedly  in  struc- 
ture in  bees  of  different  ages.  In  the  newly  emerged  bee  the  epider- 
mis which  underlies  the  wax  plate  is  composed  of  epithelial  cells 
nearly  cubical  in  form.  As  the  bee  grows  older  these  cells  become 
elongated  and  are  separated  by  clear  spaces,  and  when  the  bee  has 
reached  the  height  of  its  activity  as  a  wax  producer  these  gland  cells 
are  elongated  and  show  liquid  wax  stored  in  the  spaces  between  them. 
"When  the  wax-secreting  period  is  over  these  cells  degenerate,  so  that 
in  sections  through  the  glands  of  old  field  bees,  or  of  bees  that  have 
lived  over  winter,  the  layer  of  cells  beneath  the  wax  plates  appeai> 
greatly  shrunken,  and  individual  cells  can  be  distinguished  by  their 
nuclei  only.  These  histological  data  are  given  by  Dreyling  in  sup- 
port of  the  conclusion  that  the  secretion  of  wax  in  much  more  abun- 
dant at  a  certain  period  in  the  bee's  life  and  that  old  bees  and  ver}' 
young  bees  are,  as  a  rule,  incapable  of  wax  production.  These  con- 
clusions are  in  harmony  with  the  practical  experiences  of  bee  keepers. 

METHODS   OF   OBSERVATION. 

In  a  study  of  the  behavior  during  scale  removal  and  wax  building 
it  is  necessary  to  watch  the  bees  while  they  are  working  naturally 
within  the  hive.  To  accomplish  this,  observatory  hives  are  used  in 
which  glass  is  substituted  for  wood  in  part  of  the  construction. 
Most  of  the  work  is  done  upon  colonies  in  modified  nucleus  boxe> 
(fig.  2).  The  two  sides  are  removed  from  each  hive  and  are  replaced 
with  glass  in  the  form  of  sliding  doors,  two  to  a  side,  and  glass  plates 
are  fitted  to  the  top.  It  all  cases  wooden  shades  cover  both  sides  and 
top  when  the  bees  are  not  under  observation.  Although  bees  are 
somewhat  disturbed  when  light  is  first  admitted  to  the  hive,  they  ap- 
pear to  become  accustomed  to  it  and  work  normally  unless  the  hive  is 
left  open  for  too  long  a  period. 

"When  a  hive  is  well  crowded  with  bees,  and  when  the  frames  are 
widely  spaced,  the  workers  are  apt  to  extend  the  comb  above  the  level 
of  the  top  bars  of  the  frames  until  it  comes  in  contact  with  the  glass. 
This  gives  the  observer  an  excellent  opportunity  to  study  the  comb 


M  wiiMi  \  I  [OS    "i     w  w    BGAJ  is  in'    i  ill     HON1  I    B  •> 

workers  at  clo  •   range,  and  it  also  obviates  the  necessity  of  placing 
glass  ends  in  the  hive  against  which  comb  might  be  built. 

Even  with  the  best  of  arrangements  ii  is  difficult  to  follow    01 
the  movements  of  the  workers  <luiiiiir  the  ad  of  scale  removal.     A 
nn  aid  to  \  iaion  :i  Zeiss  binocular  microscope  is  used,  the  tubes  being 
removed  from  the  stand  and  held  to  the  eye  after  the  manner  of  :i 
By  the  use  of  this  instrument  a  bee  appears  to  acquire 


Fu..  2. — Observatory  hive,  aw  fitted  with  Midi.—  glass  doors,  and  tw.>  p 

glass  cover  tiu>  top.     The  sliding  glass  doors  allow  the  obaerrer  to  gain  access  I 

i  :iro:i  of  I  comb  without  removing  t ho  glass  from  tli"  entire  Bide  <>f  Ihr 

hrre.     Bcreens  of  wood  cover  the  glass  of  tin-  rides  and  t"i>  when  '  -  nol  under 

observatl  >n.     (Original.  > 

the  dimensions  of  a  large-sized  rat,  and  the  action  of  its  l<\Lr-  and 
mandibles  may  be  followed  with  great  precision. 

For  the  sake  of  later  identification  many  of  tin-  bees  are  ma 
by  painting  different  colors  on  their  hacks,  and  some  are  numb 
Such  distinctive  marks  make  it   possible  to  follow  the  actions  of  an 
individual  1hh>  from  day  to  day. 

The  observations  here  recorded  were  made  during  the  summer  of 
1911  at  the  apiary  of  the  Bureau  of  Entomology. 


MANIPULATION    OF    WAX    SCALES    OF    THE    HONEY   BEE. 


REMOVAL  ()]'  THE   WAX   SCALES. 


Fig.  3. — Ventral  view  of  a  worker  bee  in  the  act  of 
removing  a  wax  scale.  The  two  middle  legs  and 
the  right  hind  leg  are  used  for  support,  while  the 
left  hind  leg  removes  the  scale.      (Original.  I 


The  determination  of  the  exact  method  by  which  the  wax  scales 
are  removed   either  comes   as  the  result  of  prolonged  and   patient 

watching  or  is  the  product 
of  good  fortune.  Long  be- 
fore the  observer  is  able  to 
decide  upon  all  of  the  de- 
tails of  the  process  he 
becomes  convinced  that 
usually  the  scales  are  re- 
moved by  the  bee  which 
secretes  them  and  by  this 
bee  are  masticated  and 
added  to  the  comb.  The 
workers  never  assist  each 
other  in  the  process  of  re- 
moval, although,  as  will 
be  mentioned  later,  free 
scales  ma)T,  in  some  ca>-e-. 
be  handled  by  other 
workers. 

As  a  rule,  the  scales  are 
removed  while  the  bee  is 
standing  on  the  comb  or  its  support,  and  the  wax  thus  obtained  is 
applied  to  the  comb  near  the  place  where  it  is  removed.  Since  the 
whole  process  of  removal  takes  place  beneath  the  worker's  body  it 
can  be  observed  most 
satisfactorily  when 
the  bee  is  seen  from 
the  side  or  when  it  is 
building  comb  against 
a  glass  plate. 

The  posture  of  a 
bee  in  the  act  of  re- 
moving a  scale  is 
rather  characteristic 
and  is  at  once  recog- 
nized by  one  familiar 
with  it.  Immediately 
before  the  scale  is  to  be 
removed  the  bee  may 
be  busily  engaged  upon  the  surface  of  the  comb,  plying  with  its  man- 
dibles the  wax  of  the  scale  last  extracted  or  reshaping  and  polishing 
wax  already  deposited,  its  whole  body  somewhat  agitated,  moving 


Fig. 


4. — Side  view  of  a  worker  in  the  same  posture  as 
that  shown  in  figure  :>.      (Original.) 


MANIPULATION    OF    w  \\    MALM  01     mik    HON] 


backward  and  forward  or  from  Bide  to  aid*  as  it  adapts  it-  poaition  t<> 
the  work  in  hand.    Suddenly  ii>  hody  becomes  very  quiet    The  fore- 
and  mandibles  are  raised  from  the  comb,  and  the  head  is  held 
with  the  face  inclined  tow 


ard   (he  comb.    The 

leg    of    one    side    i- 
raised,    and 


innl 

now 

its    Battened 

or 


''"•■  ■"•  Ventral  riew  of  a  worker  bee  showing  the 
position  of  the  was  scale  )us1  before  11  is  grasped 
by  tin'  forelegs  and  mandibles.  The  scale  is  -till 
adhering  t.>  the  spines  <<(  the  i»«»i t.-n  combs.  The 
i-  supported  npon  the  two  middle  legs  and 
up. .ii  the  bind  leg  which  is  n  >t  remoylng  the  scale 
(Original.) 


Brs(  tarsal  segment 
planta  is  slipped  along  the 
ventral  surfa<  e  of  the  ex- 
tended abdomen  and  comes 
in  contact  with  the  pro 
trading  was  scales  of  the 
corresponding  aide  (figs. 
:'>  and  I >.  The  weight  of 
the  bee  is  oow  supported 
upon  three  legs;  upon  the 
middle  leg  of  the  side 
from  which  the  scale  is  to 
be  removed  and  upon  the 
middle  and  hind  legs  of 
the    other    side.      The    first 

tarsal  segment   <d'  the  leg 

which     is     to     remove     the 

scale  is  now  pressed  firmly 
■gained  the  abdomen,  and  the  edge  of  a  protruding  scale  becomes 
engaged  with  it.  steady,  continuous  pressure  is  now  exerted  both 
against  the  abdomen  and  toward  the  rear,  with  the  result  that  the 

Scale  is  drawn  out  of  its 

pocket  but  remain  at- 
tached to  the  leg  which 
removed  it.  The  hind 
leg  bearing  the  scale  is 
now  quickly  Hexed  tow- 
ard the  thorax  and 
head,  thus  carrying  tin- 
scale  forward  under  the 
hody     of     the     hee     and 

placing  it  in  a  position 

where  it   may  he  readily 

grasped  by  the  forelegs 
or  the  mandibles  (figs.  5  and  6).  Sometimes  the  scale  is  appar- 
ently removed  from  the  hind  leg  by  the  mandibles  alone,  hut  Usually 
the  forelegs  aid  in  this  process  and  also  manipulate  the  scale  while 


Bide  vii-w  nf  ;i  worker  bee  in  the  <amo  pocrore 

;is  thai  Bhown  in  li.-iir.-  r.      (Original.) 


8 


MANIPULATION   OF   WAX   SCALES   OF   THE   HONEY  BEE. 


the  mandibles  are  masticating  it.     After  the  scale  has  been   thor- 
oughly masticated  the  wax  is  applied  to  the  comb. 


THE    SCALE-REMOVING-  ORGAN. 

A  point  of  particular  interest  in  the  process  of  wax  scale  removal 
is  that  which  deals  with  the  manner  in  which  the  scale  is  grasped  by 

the  hind  leg  which  removes  it.  As  is 
well  known,  each  hind  leg  of  the  worker 
bee  bears  a  pincerslike  structure — the 
so-called  wax  shears — located  at  the 
juncture  of  the  tibia  and  the  flattened 
first  tarsal  segment  or  planta  (fig.  7). 
According  to  the  statements  of  numer- 
ous writers,  the  wax  scales  are  grasped 
between  the  edges  of  the  supposed 
pincers  formed  by  the  pecten  above  and 
the  auricle  below,  and  are  either  snipped 
off  or  are  held  by  the  jaws  of  the 
pincers  and  thus  drawn  from  the  pock- 
ets. Cowan's1  account  may  be  given 
as  typical  of  others  which  are  current 
in  the  literature  of  apiculture  and  of 
zoology. 


T/B/s4-- 


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WAX 


Fig.  7. — Inner  surface  of  the  left 
hind  leg  of  a  worker  bee,  show- 
ing the  position  of  a  wax  scale 
immediately  after  it  has  been  re- 
moved from  the  was  pocket.  The 
scale  has  been  pierced  by  seven 
of  the  spines  of  the  pollen  combs 
of  the  first  tarsal  segment  or 
planta.  The  jaws  of  the  so- 
called  wax  shears  or  pincers  are 
formed  by  the  pecten  spines 
above  and  the  surface  of  the 
auricle  below.      (Original.) 


The  articulation  of  the  tibia  and  planta 
being  at  the  anterior  angle,  and  the  absence 
of  the  spur  on  the  tibia  (which  only  the 
honey  bee  does  not  possess)  give  the  pecten  a 
freedom  of  action  it  would  not  otherwise  have 
and  enable  it  to  be  used  together  with  the 
auricle  on  the  planta.  which  is  quite  smooth, 
as  a  true  pair  of  pincers,  and  as  an  instru- 
ment for  laying  hold  of  the  thin  flakes  of 
wax,  and  for  bringing  them  forward  to  be 
transferred  by  the  other  legs  to  the  jaws  for 
manipulation. 

As  a  matter  of  fact,  the  wax  shears 
have. nothing  whatever  to  do  with  the 
removal  of  the  wax  scales.  They  per- 
form an  entirely  different  function,  be- 
ing concerned  with  the  gathering  of 
pollen  in  a  manner  to  be  described  in  a 


future  paper. 

In  coming  to  the  above  conclusions  the  writer  was  first  convinced 
that  the  so-called  wax  shears  are  not  used  in  removing  scales  by 
Loting  that  the  position  of  the  tibio-tarsal  joint  at  the  time  of  scale 


1  Cowan,  T.  W.,  "  The  Honey  Bee,"  2d  ed.,  London,   1904. 


MWIi'l    I    \lloN     n|      WA\    St   All. S    OF    TH1     BON] .',      Ull.  0 

removal  is  Buch  as  to  make  il  impossible  for  the  pincerslike  crei 
ic»  grasp  the  scale.    Moreover,  the  open  jaws  of  the  shears  poinl  hit  - 
terally  and  away   from  the  ither  than  toward   them,  nor, 

indeed,  is  it  possible  for  the  shears  to  grasp  even  the  projecting  edj 

m\     f  the  ventral  or  lateral  body  plates  and  thus  steady  or  guide 
tlu>  leg  as  it  seeks  contact  with  the 

The  transverse  rows  <>!'  Bpines  upon  the  planta,  called  pollen  combs, 
iiinl  not  the  was  shears  are  instrumental  in  the  removal  of  scales. 
Snodgrass  (1910),  in  discussing  the  anatomy  < > f  the  hind  leg  and 
,i~  functions,  states  that  the  wax  is  "poked  out  of"  the  "pockets 
by  means  of  the  Bpines  on  the  feet  '"  "  with  the  ordinary  hairs  or 
spines  i  i  the  tibiae  or  tarsi,"  and  the  same  general  conclusions  were 
reached  independently  by  the  writer,  but  with  this  exception;  only 
the  spines  of  the  first  tarsal  segment  (planta)  function  in  this 
manner,  and  usually  <  nly  certain  large  spines  in  the  rows  at  the  dis- 
tal end  of  this  segment 

It  is  exceedingly  difficult  to  capture  a  bee  at  the  very  moment  at 
which  the  scale  is  being  drawn  from  its  p<  cket  and  before  it  has  been 
carried  to  the  month,  and  even  if  this  is  acc<  mplished  the  captive  is 
very  likely  to  drop  the  scale  from  the  hind  leg  in  it-  struggles  to 
escape.  If.  however,  one  i>  successful,  the  scale-removing  leg  will 
show  the  little  wax  scale  adhering  to  the  distal  end  of  the  inner 
surface  of  the  first  tarsal  segment,  being  pierced  in  several  pla 
by  the  stn  Dg  Spines  which  project  from  the  lower  rows  of  the  pollen 
combs.     (See  liir.  T.) 

It  can  also  he  shown  experimentally  that  this  method  of  remov- 
ing the  wax  scales  is  entirely  possible,  for  if  the  hind  tarsus  of  a  bee 
i>  mounted  upon  a  small  -tick  an. I  i-  gently  rubbed  ah  ugthe  ventral 
side  of  a  fully  extended  dead  bee's  abdomen,  holding  it  in  such  a 
p'  sition  that  the  pollen  combs  brush  over  the  projecting  edges  of  the 

les,  one  of  the  scales  will   probably  be  removed  and   will  be  seen 
adhering  to  the  spines  in  the  manner  above  described. 

In  any  hive  where  comb  i>  being  constructed  rapidly  many  free 
scales  will  be  found  upon  the  bottom  board  and  upon  the  lower  bars 
of  the  frames.  If  these  scab-  are  examined  microscopically  some 
will  lie  found  without  mark-  upon  them,  having  evidently  been 
lot  sened  from  their  pockets  accidentally  during  the  movements  of 
the  worker-  over  the  comb  and  around  the  hive.  Others  will  --how 
certain  marks  ami  scratches  upon  them,  indicating  that  they  were 
voluntarily  removed  from  the  picket-,  and  in  some  ca-es  they  may 
bear  the  mark-  of  the  mandibles,  showing  thai  they  were  dropped 
during  the  process  of  mastication.  Most  of  tin  scales  which  are 
marked  at  all  are  indented  with  several  small  puncture-  showing  the 
places  where  the  spines  of  the  pollen  comb.-  have  pierced  them. 
These  .-cars  are  exactly  similar  in  appearance  to  those  on  the  scale 


10  MANIPULATION    OF    WAX    SCALES   OF    THE    HONEY   BEE. 

shown  in  figure  7.  Such  free  scales  are  not  marked  as  they  would  be 
had  they  been  extracted  By  such  a  structure  as  the  so-called  wax 
shears. 

So  far  as  can  be  determined  there  does  not  appear  to  be  any  regu- 
lar order  for  the  removal  of  scales.  One  may  be  taken  from  the 
left  side  and  then  one  from  the  light,  or  the  bee  may  remove  two  or 
three  from  one  side  in  succession.  An  attempt  to  remove  a  scale  is 
by  no  means  always  successful,  the  worker  often  trying  first  one  side 
and  then  the  other,  pressing  the  pollen  combs  against  the  more  ante- 
rior scales  and  running  them  down  to  the  most  posterior,  until  at 
last  a  scale  is  impaled  upon  the  spines  or  the  bee  discontinues  its 
efforts. 

FURTHER  MANIPULATION  AND  THE  MASTICATION  OF  SCALES. 

When  a  scale  has  become  attached  to  the  spines  it  is  transferred  to 
the  mouth  with  great  rapidity,  so  swiftly,  in  fact,  that  the  e3re  can 
scarcely  follow  the  action.  This  is  not  surprising,  for  it  is  necessary 
only  to  flex  the  leg  toward  the  head  to  bring  the  scale  in  close  con- 
tact with  the  forelegs  and  mandibles.  The  leg  is  rotated  through 
the  arc  of  a  circle,  downward,  forward,  and  upward,  while  at  the 
same  time  the  head  is  slightly  turned  under  to  receive  the  scale. 
The  process  of  mastication  is  more  prolonged.  It  is  usually  sup- 
posed that  the  pure  wax  of  the  scale  differs  in  chemical  composition 
from  the  wax  of  the  comb,  this  change  being  accomplished  during 
mastication,  by  which  process  the  wax  is  mixed  with  saliva,  becomes 
translucent  rather  than  transparent,  changes  somewhat  in  color,  and 
becomes  more  pliable. 

The  behavior  of  a  bee  upon  receiving  a  wax  scale  at  its  mouth  is 
subject  to  considerable  variation.  On  some  occasions  the  scales  are 
apparently  manipulated  by  the  mandibles  alone,  while  at  other  times 
the  forelegs  are  brought  into  requisition  and  assist  the  mandibles. 
"When  a  scale  is  thin  and  small  and  has  been  firmly  grasped  by  the 
mandibles  little  assistance  is  needed  from  the  legs.  But  if  a 
scale  of  medium  or  extra  thickness  is  presented,  or  if  the  mandibles 
do  not  hold  it  securely  and  it  is  in  danger  of  falling  from  the  mouth, 
the  two  forelegs  are  used  to  great  advantage  in  readjusting  the  scale 
and  in  so  holding  it  that  the  mandibles  may  be  applied  to  it  most 
advantageous!}'.  If  a  scale  is  small  and  thin,  it  may  be  masticated 
entirely  before  any  wax  is  applied  to  the  comb;  but  if  of  considerable 
size  a  portion  only  may  be  prepared,  this  deposited  upon  the  comb, 
and  then  the  remainder  treated  in  a  similar  manner. 

As  a  rule  the  wax  which  is  deposited  upon  the  comb  by  the  pro- 
ducing bee  is  first  subjected  to  the  action  of  the  mandibles  and 
mixed  with  saliva.  Such,  however,  is  not  always  the  case,  for  some 
bees  appear  to  be  "  careless  "  and  will  mingle  small  unchewed  por- 
tions of  scales  with  the  masticated  wax.     Indeed,  it  is  not  uncom- 


M  win  i  \  I  h>\    0]    \\\\    BCALBB  OF  TH1    B0VX1    BBB.  11 

mon  to  find  Dearly  perfect  Bcales  mixed  with  the  wax  of  a  newly 
made  comb.    The  masticated  wax  itself  is  Bpongy  and  flaky  when 
it  i-  deposited   by  the  producing  bee  and    will  Later   be  reworl 
thereby  gaining  greatly  in  compactness  and  smoothne 

The  entire  process  <>t'  the  removal  of  >  ne  scale,  its  mastication,  and 
tin-  application  of  the  was  to  the  comb  is  completed  in  :i I >« mi  four 
minutes,  only  a  very  small  portion  of  this  interval  being  consumed  in 
the  work  of  extracting  the  scale  frOm  it-  pocket  and  passing  ii  to  i luj 
mouth,  except  in  cases  in  which  scales  appear  t<>  be  removed  with 
difficulty. 

1  I.I  I      -<    \|,KS. 

When  wax  scales  are  voluntarily  removed  they  are  taken  ofT  by 
the  bee  which  secretes  them  and  in  the  manner  above  described. 
Many,  however,  an'  accidentally  detached,  being  loosened  from  their 
pocket-  by  movements  of  the  abdomen,  incidental  cleansing  move- 
ments of  the  legs,  or  by  contact  with  objects  both  within  and  without 
the  hive.  Such  scales,  and  also  those  which  are  dropped  in  the 
course  of  transference  from  the  wax  pocket  to  the  mouth,  may  or 

may  not    be  recovered   later  and   added   to  the  comh.     Since  old   wax 

is  used  over  and  over  again  in  the  rebuilding  of  comb,  it  i-  hut 
natural  to  expect  that  scattered  scales  would  likewise  be  utilized  by 
the  colony  and  not  be  allowed  to  go  to  Waste,  and  it  is  probably  true 
that   such   is  DSUally  the  ca-e.      Yet    there  appeal's  to  he  no  concerted 

action  among  the  workers  to  salvage  Buch  particle-  of  wax,  no  class 
of  comb  workers  whose  duty  it  is  to  pick  such  material  from  the 
hottom  board  of  the  hive  and  carry  it  to  the  comb.  Scales  which 
drop  are  likely  to  remain  for  a  long  time,  and  some  may  even  he 
carried  out  through  the  entrance  with  waste  material.  If.  however. 
Male-  accidentally  dislodged  or  voluntarily  removed  fall  on  the 
comb  among  the  comb  workers  they  are  often  noticed  by  them,  picked 
up.  masticated,  and  built  into  the  comb.  If  a  scale  -lip-  from  the 
pollen  comix  or  is  fumbled  by  the  bee  before  being  grasped  by  the 
mandibles,  it  i-  seldom  recovered  by  the  worker  to  which  it  Ixdongs 
Hide--  it   fall-  very  near  her  or  she  -tumhle-  upon  it  accidentally. 

PARTI  W.    KIMi'V  W.   OP    S(   AI.K.S. 

Although  a  bee  endeavor-  to  remove  an  entire  wax  scale  at  one 
operation,  the  attempt  i-  not  always  successful.  A  scale  that  lias 
become  very  thick  is  difficult  of  removal,  particularly  so  if  the  outer 
edge  is  broken  or  beveled.    When  the  hec  applies  its  pollen  combs  to 

such  a  scale  the  spine-  may  fail  to  get  a  hold  upon  the  wax.  or  they 
may  not  become  sufficiently  well  fixed  in  it  to  make  possible  the  re- 
moval of  the  entire  male.  Instead  of  this,  shreds  and  small  pieces  of 
wax  arc  turn   oil    and   remain  -ticking  to  the  bristles  of  the  pollen 


12  MANIPULATION    OF   WAX   SCALES   OF   THE   HOSTEY  BEE. 

combs.  These  may  be  entirely  disregarded  by  the  bee,  or  they  may 
be  cleaned  off  by  scraping  the  combs  together,  the  shreds  of  wax 
dropping  to  the  bottom  of  the  hive.  More  usually,  however,  if  a 
worker  is  actively  engaged  in  the  task  of  adding  to  the  comb  these 
hits  of  wax  will  be  carried  forward  to  the  mouth,  masticated,  and 
applied. 

In  one  case  which  came  under  observation  a  worker  had  removed 
all  of  its  wax  scales  except  a  very  large,  thick  one  which  was  evi- 
dently sticking  tightly  in  its  pocket.  Repeated  efforts  were  made  by 
the  bee  to  accomplish  the  extraction  of  this  scale,  but  with  only 
partial  success,  since  the  main  portion  of  the  scale  remained  in  the 
pocket.  But,  as  the  result  of  its  efforts  the  bee  succeeded  in  beveling 
off  the  entire  projecting  edge  of  the  scale,  rasping  it  off  bit  by  bit 
and  carrying  the  small  pieces  forward  to  the  mouth,  masticating 
them,  and  dispositing  the  wax  upon  the  comb. 

PRODUCERS  AND  BUILDERS. 

The  presence  of  well-developed  scales  protruding  from  the  pockets 
of  a  worker  does  not  necessarily  indicate  that  this  individual  will 
shortly  add  this  wax  to  the  comb,  even  though  the  colony  may  at  the 
time  be  producing  comb  at  a  rapid  rate.  Such  a  bee  may  be  working 
upon  the  comb  as  a  molder  of  wax  rather  than  as  a  producer.  One 
who  is  intent  upon  a  study  of  the  process  of  scale  removal  will  often 
be  disappointed  after  following  for  a  time  the  movements  of  a 
worker  that  is  evidently  manipulating  wax  and  which  shows  the 
protruding  edges  of  scales  beneath  its  abdomen,  for  the  wax  with 
which  it  is  working  is  being  picked  up,  little  bjr  little,  from  the  comb 
and  comes  not  from  its  own  body.  This  reworking  of  wax  is  one  of 
the  most  characteristic  features  of  comb  construction,  for  it  goes  on 
continually  while  new  comb  is  being  produced,. and  it,  is,  of  course,  a 
necessary  process  in  the  reconstruction  of  old  comb. 

The  claim  has  been  made  by  several  investigators  and  writers  that 
the  bees  which  sculpture  the  wax  are  not  at  the  same  time  concerned 
with  its  secretion  and  deposition — that  there  are  producing  bees 
and  building  bees.  In  a  sense  this  is  true,  but  not  entirely  so.  With- 
out doubt  many  active  comb  workers  are.  at  the  time,  nonproductive, 
for  the  wax  glands  of  many  are  not  functionally  active.  The  re- 
sults of  Dreyling  would  indicate  that  the  old  bees,  at  least,  might  be 
considered  as  falling  in  this  class,  and  the  direct  observations  of  the 
writer  lead  to  the  conclusion  that,  old  bees  devoid  of  wax  scales  per- 
form a  considerable  share  of  the  labor  of  reworking  newly  deposited 
wax  and  of  shaping  and  polishing  the  cells  of  the  comb. 

However,  as  noted  above,  bees  with  well-developed  wax  scales 
often  busy  themselves  with  wax  working  rather  than  with  produc- 
tion.    Moreover,  a  bee  that  is  removing  its  scales  may  discontinue 


MANIPULATION    0]     WAX  80ALE8  01     VBX  H0NS1    B  1 .5 

this  work  and  give  its  attention  tu  the  molding  of  wax  laid  down 
l)\  others.  This  may  occur  immediately  after  a  worker  has  removed 
lies,  or  the  bee  may  turn  to  sculpturing  while  Beveral 
yet  remain  in  the  pockets.  Ii  is  thus  evidenl  thai  the  produc- 
ing bee  may  also  be  a  worker  of  wax  produced  by  others  ami  that 
nonproductive  bees  do  m>t  monopolize  the  work  of  Bculpturing  and 
polishing  the  comb. 

-I    M  M  KB1  . 

A-  is  well  known,  the  wax  produced  by  the  worker  bee  occurs  in 
tlii>  form  of  scales,  eight  in  number,  which  appear  upon  the  surfaces 
of  (lie  eight  wax  plates.  These  wax  plates  arc  located  upon  the 
last  i'mir  visible  ventral  plates  of  a  worker  bee's  abdomen.  The  wax 
reted  by  glands  which  lie  upon  the  inner  surface  of  each  wax 
plate.     The  liquid  wax  exude-  through  poi  ich  perforate  the 

Wax  plate-,  and   it   harden-  to   form  the  scales  a-  il    conic-   in  contact 
with  the  air. 

Unless  accidentally  dislodged  the  wax  scales  are  always  removed 
and  manipulated  by  the  bee  which  secretes  them. 

in  the  process  of  removal  the  scale  is  not  grasped  by  the  so-called 

wax  shears,  hut  it  i>  pierced  by  a  few  of  the  -till'  -pine    on  the  distal 

end  of  the   first   tarsal   segment    of  the  hind   leg  and    i-   then  drawn 

from  it-  pocket  and  remain-  adhering  to  these  -pine-  until  removed 

■  ia.-ticat  ion. 

By  flexing  the  hind  leg  the  scale  i-  brought  f<  rward  beneath  the 
bee's  body  and  into  proximity  with  the  mouth.     In  the  proce 
mastication  the   forelegs  usually  aid  the  mandibles  by  holding  the 
scale  in  an  advantageous  position. 

Xo  definite  sequence  i-  observed  by  the  bee  in  the  order  in  which 
it  removes  it-  scales. 

a  rule  entire  scales  are  removed  at  one  operation,  although  it 

times  ha]  | -  thai  ;i  thin  scale  is  broken  in  extracting  it  from 

its  pocket  or  an  extremely  thick  one  is  gradually  beveled  off  by  the 
continued  rasping  of  the  pollen  combs. 

Scales    which    are    removed    accidentally    or    which    are    dropped 
during  manipulation  may  he  recovered  later  and  built  into  the  i 
hut  the  recovery  of  free  scales  is  usually  not  accomplished  by  the 
bee  which  secreted  them. 

ich  are  producing  wax  may  also  rework  the  masticated 
W0K  laid  down  by  other-.  Producing  bees  may  turn  to  the  work  of 
building  and  sculpturing  the  comb  either  before  all  their  scales 
are  removed  or  immediately  after  this  has  been  accomplished. 

o 


UNIVERSITY  OF  FLORIDA 


3  1262  09216  5934 


.      t 


